Given that psychopathy is associated with narcissism, lack of insight, and pathological lying, the assumption that the validity of self-report psychopathy measures is compromised by response distortion has been widespread. We examined the statistical effects (moderation, suppression) of response distortion on the validity of self-report psychopathy measures in the statistical prediction of theoretically relevant external criteria (i.e., interview measures, laboratory tasks) in a large sample of offenders (N = 1,661). We conducted 378 moderation and 378 suppression analyses to examine the response distortion hypothesis. The substantial majority of analyses (97% moderation, 83% suppression) offered no support for this hypothesis. Nevertheless, suppression analyses revealed consistent evidence that controlling for response distortion slightly increased the relations between the fearless dominance and coldheartedness features of psychopathy and maladaptive outcomes. Our findings are largely inconsistent with the popular notion that the validity of self-report psychopathy measures is markedly diminished by response distortion. Further research is necessary to determine whether these findings generalize to other populations or contexts.